The invention relates to    A) from 10 to 99.99% by weight of a polyamide,    B) from 0.01 to 20% by weight of a high-functionality polyetherol with an OH number of from 3 to 1350 mg KOH/g of polyetherol (to DIN 53240, part 2)    C) from 0 to 70% by weight of further additives,    where the total of the percentages by weight of components A) to C) is 100%.
The invention further relates to the use of the molding compositions of the invention for the production of fibers, foils, and moldings of any kind, and also to the resultant moldings.
Thermoplastic polyamides, such as PA6 and PA66, are often used in the form of glassfiber-reinforced molding compositions as materials in the design of components which during their lifetime have exposure to elevated temperatures, with thermooxidative degradation. Although the thermooxidative degradation can be delayed by adding known heat stabilizers it cannot be prevented in the long term, and becomes apparent by way of example in a reduced level of mechanical properties. It is highly desirable to improve the heat-aging resistance (HAR) of polyamides, since this can achieve longer lifetimes for components subject to thermal stress, or can reduce the risk that these will fail. As an alternative, an improved HAR can also permit the use of the components at higher temperatures.
EP-A 1 424 360 discloses branched polyether/polyglycerols of different structure, these being intended to increase the flowability of thermoplastics.
The heat-aging resistance (HAR) of the known molding compositions remains inadequate, in particular over prolonged periods of thermal stress.